1. Field of the Invention
This invention relates to the lubrication of extrusion tools in presses for the extrusion of metal. The invention is applicable to presses for the extrusion of solid or profiled sections and tube-extrusion presses. The press can be of the direct or indirect extrusion type.
2. Description of the Prior Art
At present, the tools, for example extrusion dies and mandrels, of extrusion presses are usually lubricated, by hand, usually with a liquid lubricant for example liquid graphite. With this procedure, the application of lubricant is performed irregularly and the application of a specified amount of lubricant cannot be ensured. Uniform lubrication is particularly difficult when a mandrel has to be lubricated: the person performing this task usually stands on one side of the press and can reach the opposite side of the mandrel only with difficulty. The distribution of lubricant is uneven. The lubricating implement is usually a stick with a cloth which is dipped into the lubricant and then applied by hand to the extrusion tool to be lubricated. The liquid lubricant tends to be splashed about, causing serious contamination of the press and the surroundings. Manual lubrication is also very labour-intensive.
Extrusion presses have also been lubricated by spraying liquid lubricant onto the extrusion tools: this is also a dirty and labour-intensive procedure.